1. Field of the Invention
The invention relates to an antenna device. The invention further relates to an antenna array, an intermediate product for an antenna device and a method for manufacturing an antenna device.
2. Description of the Prior Art
Antenna devices are generally known and used for receiving and emitting electro-magnetic radiation and may, for example, be employed in radar and other direction finding systems, astronomical observatories and satellite receiving equipment, for example. Often, an antenna device has to receive or emit electro-magnetic radiation with differing spatial properties, for example electro-magnetic radiation with different directions of polarization or electro-magnetic radiation stemming from different sources (and, accordingly, emitted from different positions).
For instance, for receiving electro-magnetic radiation with different polarizations dual polarized antenna devices are known. A dual polarized phased-array antenna is known, for example, from the European patent publication 0 349 069 A1. This prior art document describes a phased-array antenna having a plurality of antenna elements positioned in a matrix-shaped arrangement. The matrix comprises an assembly of two orthogonal sets of parallel insulating planar supports. Each of the insulating planar supports is provided with a conductive surface layer patterned to form a succession of tapered notch antenna elements. The tapered notch antenna elements are distributed along an outward facing edge of the planar support. Each of the tapered notch antenna elements has a polarization parallel to the planar supports. The phased-array antenna thus comprises two orthogonal sets of line-shaped arrangements of tapered notch antenna elements, of which sets each has a respective, orthogonal polarization.
In the phased-array antenna described in the above mentioned patent publication, the insulating planar supports of each set intersect and engage on the supports of the other set. To that end, the supports are provided with a slot extending from the edge of a planar support to half way across the support. The sets are positioned such that the supports of one set extend in the slots of supports of the other sets. The supports of one set thus intersect and engage with the supports of the other set to form a matrix-shaped support structure.
However, a draw-back of the antenna device described in said patent publication is that each planar support has to be provided with a multitude of slots, in which thereafter the supports of the other sets have to be positioned. Accordingly, manufacturing of the dual polarized phased-array antenna is complex. Furthermore, the planar supports have to be made of a rigid material in order to obtain a support construction with sufficiently high stiffness, which limits the choice of materials which can be used in the antenna device.